Thinner PS Fluid?

[Sluggo0018]

My daughter drives a 2008 Ford Taurus with roughly 200,000 miles. We live in northern NJ.

Lately she has been commenting about how the power steering is a lot stiffer with the cold temperatures. She says that until the car warms up, she must return the steering wheel manually to straight ahead after a turn. It does not self center until warmed up.

A few years ago I changed most of the fluid by repeatedly draining and refilling the PS reservoir with a lot of turning of the steering wheel in between. I cannot recall the brand of fluid that I used, but I am sure that it met the correct specifications.

Based on the described conditions, is there a specific brand or grade of PS fluid or additive that may perform better in the colder temperatures? I am assuming that this issue is at least partially related to the viscosity of the current fluid.

Thanks in advance for any help you can provide.

 

[Oro_O]

The biggest part of it may be simply wear. I have found most ps pumps to need replacement between 175k and 250k miles. Applications vary, but if it has fresh fluid like you describe and it's full, that should be a consideration. Is it leaking?

 

[Whimsey]

I don't know if using a thinner ATF for the Ford PS is advisable. I think I'd try a synthetic ATF first, like Mobil 1 ATF. Though it sounds like possible mechanical issues brewing in the PS system. Try a synthetic ATF first, that's the cheapest way as it should work better in colder temps. My 2002 F-150 worked much better in the cold when I used the synthetic Mobil 1 ATF in place of the non synthetic ATF. My issue with the 2002 was not steering hanging up but the horrible Ford cold temp PS whine using non synthetic ATF. I live in NW NJ also, so good luck if you have to replace anything or try to remove a well rusted PS fitting

.

Whimsey

 

[tcp71]

could be the steering half shaft U-Joints binding until the joint inside the car warms up.

 

[Linctex]

Try Mercon LV?

(Low viscosity?)

 

[crainholio]

What fluid did you put into it? I used Castrol high mileage Dex/Merc in my '05 Mercury Mariner (Ford Escape) and did a flush via the reservoir return hose...faster than multiple drain & fills and more thorough. Of note, the reservoir had a filter screen inside and it was covered in black solids when removed prior to the flush. I spent time back-flushing the reservoir until it was clean before reinstalling and plumbing the flush hose.

 

[Sluggo0018]

Or : I don't see any leakage.

crainholio: I cant recall what fluid I used when I changed the fluid several years ago.

Seem like a good first step would be trying the Mobil 1 synthetic.

 

[StevieC]

Because it changes with temperature I would be inclined to think it's the pump especially with the mileage.

 

[Snagglefoot]

May I suggest this. I've been using it in my 2005 Ford Taurus. It really quiet downed the whine and works just fine in cold temps.

 

[crainholio]

Originally Posted by Snagglefoot
May I suggest this. I've been using it in my 2005 Ford Taurus. It really quiet downed the whine and works just fine in cold temps.



That stuff leaked in my '09 Subaru Forester after I flushed it in at ~80K miles. Driver side steering rack boot was soaked at the next oil change with red droplets hanging off of it. Just a data point on a vehicle not similar to yours or the OPs. Subsequent flush with the same Castrol high mileage Dex/Merc I had used on the '05 Mercury, and a few cleanups of the boot, eventually got it dried out and back to normal.

 

[JMJNet]

There is a Maxlife PS fluid also in a red bottle looks similar to the ATF.

I will just flush the current fluid and replace the whole with new fluid.
What you want is better more stable viscosity fluid NOT thinner fluid.
That can be accomplished by having new/clean fluid in the system.

 

[dogememe]

Lubegard Complete Synthetic Power Steering Fluid. Readily available at O'Reilly or Amazon.

 

[RyanY]

Originally Posted by JMJNet
There is a Maxlife PS fluid also in a red bottle looks similar to the ATF.

I will just flush the current fluid and replace the whole with new fluid.
What you want is better more stable viscosity fluid NOT thinner fluid.
That can be accomplished by having new/clean fluid in the system.


Just a note on Maxlife PS fluid, which I used in my Cad a few years ago. It worked just fine but steering was "stiffer" than with OEM. Maxlife PS is thicker than regular Valvoline PS fluid (see documentation). I also hoped it would solve the notch or catch when I turned to the right but it did not. I then switched to Lucas PS which is thinner. Turns were much easier and no more notchy turns. I also put it in my Honda and turns are a little smoother and easier. I have had no problems with Lucas PS fluid (the one marked "for all...even Honda") and I think it is great stuff.

I realize Lucas is not a favorite here, but that is just my experience. IMO it is worth the extra $$ at least for this application. I have not tried their other products so I cannot speak to their quality, but I would not hesitate to try them.

Just remembered that I did try Lucas fuel system cleaner...did absolutely nothing as far as I could tell! (Techron is better IMO). I also tried Lucas speed wax and interior cleaner. Both a little spendy but top notch. Sometimes you gets what you pays for, and sometimes you don't...

 

[zrxkawboy]

My first guess would be a worn rack.

 

[GZRider]

You could use a thinner synthetic fluid at the edge of the spec and it may help reduce steering effort, depending on the system but the pump is also likely worn. Using a quality synthetic like the Mobil1 or Redline will significantly diminish the difference in hot vs cold steering effort though. When I did the turkey baster drain and fill on my g37 at 76k miles I first used Eneos Eco ATF a very thin MaticJ/S spec fluid, drove it about 1,000 miles with the reduced steering effort, before doing the final drain and fills with Redline D6 ATF which made the steering firmer again but has zero difference between hot and cold performance and nominally better road feel.

 

[Oro_O]

Originally Posted by zrxkawboy
My first guess would be a worn rack.


Exactly - no leaks, not low, fresh fluid - but near the end of typical service life. First on the list of causes would not be fluid, but mechanical reasons.

 

[jeff8407]

Unfortunately, I think the culprit is not fluid related. Replaceing the fluid may helpm but I susppect parts may be wearing.

Typically, the O-rings begin to flatten out and fluid leaks past them. Once the car heats up, parts expand, rubber get more pliable, and pressure increases making he steering work better. I think I'd try rebuilding the pump first--just rings and seals. If that doesn't help, then go to the steering rack...